Threading die



Original Filed Jan. 2, 1935 2 Sheets-Sheet l 24 2/ Zla /5 Z Z /9 Zinnentor W/LZ/AM 0. THEM/E5 w. 0. TH EWES THREADING DI E Original Filed Jan. 2, 1935 2 Sheets-Sheet. 2

I /9 f; j /7 20 i ii illi-74% v N inventor W/ZZ/AM 0. THEWES (lttomeliis Patented Mar. 1, 1938 UNITED STATES PATENT OFFICE signor to The Ridge Tool Company,

Ridgeville,

Ohio, a corporation of Ohio Original application January 2, 1935, Serial No. 4, now Patent No. 2,076,831. Divided and this application November 4, 1935, Serial No. 48,114.

1 Claim.

This invention relates to pipe threading tools or die stocks.

a The primary object of the invention is to provide, in tools of this class, an improved type of ratchet mechanism whereby the tool or die stock may be easily and quickly changed over from a ratchet type die stock to a solid type die stock, or one wherein theratchet mechanism; is released and the threading operation carried on by turning the die stock continuously in one direction. In such instances, the work is ofttimes heavy and requires considerable leverage to effect the threading operation. Another advantage of the present tool is that the ratchet mechanism is so constructed as to be capable of withstanding relatively great thrust, while at the same time being capable of quick and easy operation or adjustment.

This application is a division of my copending application Serial No. 4, filed January 2, 1935.

The foregoing and other objects and advantages will become apparent from the following description taken in conjunction with the drawings, wherein:

Figure 1 is a view in end elevation of a thread cutting tool or die stock embodying the features of the invention, one of the chaser cam posts being shown in section;

Figure 2 is a View in section and side elevation, the part in section being taken along the line 2-2, Figure 1;

Figure 3 is an elevational view of the chasercarrier or housing and ratchet or drive ring in assembled relation together with the ratchet mechanism;

Figure 4 is an enlarged fragmentary view of the ratchet mechanism and adjacent parts;

Figures 5 and 6 are detail perspective views of a pawl cam and cam lever.

The improved tool comprises a chaser carrier plate or housing generally indicated at A, a drive ratchet ring generally indicated at B, a workholder generally indicated at C, a cam post plate D, and a backing plate E. Since the present invention is concerned primarily with the ratchet mechanism, the remaining parts of the tool need only be described sufficiently to bring out the operation of the tool.

The chaser carrier or housing is preferably made of die cast material, or is a die casting, the preferred construction of this part of the assembly being best shown in Figure 3. The central portion of the housing is shown with a threaded barrel 5 on which the workholder C is adapted to be threaded. The chasers, one of which is shown at 6 in Figure 2, are mounted in a plurality of radial slots formed in the carrier housing. The cut-out portions indicated at 9 and H! are simply formed inthe housing A to lighten the casting without detracting from its strength. The chasers are preferably resiliently held in position by' means of resiliently mounted detent members, not here shown, since they form no part of the present invention. The cutters are permitted a certain amount of retraction or backing-01f movement during the threading operation in order to provide a certain amount of taper on the threaded pipe end, cam posts l2 being provided and at their lower extremities project through registering holes I 211 formed in the backing plate E and chaser carrier plate A.

The drive or ratchet ring B is provided with handle sockets l5 and a plurality of internal teeth IS. The ratchet mechanism consists of a pair of oppositely disposed pawls or dogs I! and Ila, which have their inner extremities disposed against an abutment l8 (note Figure 4) which is preferably formed integrally with the chaser carrier A. At the lower or outer extremity of the abutment IS, a pawl retaining boss or member I9 is provided and is also formed integrally with the said carrier. Springs and 20a normally urge the pawls I1 and llw outwardly into engagement with the teeth of the drive ring B. A pawl cam 2|, shown more or less in detail in Figure 5, is provided and is formed with a cam portion or toe 2la which rides on the boss l9 and at its opposite side edges is formed with cam surfaces 2| b adapted to engage the pawls l1 and l'lm and move the latter clear of the teeth [6 when the cam member 2| is moved in an arcuate path by means of the lever 22, note Figure 6. Lever 22 is provided with an eccentrically disposed pin 22a adapted to engage in a slot 23 formed in the cam member 2|, note Figure 3. The cam member 2| is formed with a plurality of detent notches or recesses 24 adapted to engage a detent or spring-pressed ball 24a disposed in the abutment l8. The lever 22 is secured on a pin 22b which is journaled in the backing plate E and is provided with a cam disc 220 which in turn carries pin 2211. To hold the thumb lever under tension, a bent spring washer 25 is arranged to bear against the disc 22b.

In operation, assuming it is desired to rotate the cutter or die stock in a thread-cutting direction, the thumb lever 22 may be turned to the right in Figure 1, thereby sliding the cam mem ber 2| against the pawl l1 and moving it clear of the ratchet teeth l6 while the pawl I la remains in driving engagement with said teeth. To run the cutter or die stock in a reverse direction or to back it off of the cut threads, the lever may be turned in the opposite direction, thereby reversing the position of the pawls, note the position of the parts in Figure 4. Assuming it is desired to use the die'as a solid die for. work over a certain size, then the cam member 2l' may be adjusted tointermediate position at which point both the dogs I! and Ila engage the ratchet teeth [6 and lock the drive ring with the chaser housing. Two handle sockets are preferably provided so that two men may workthe same tool,

in construction and may be easily and quickly replacedin the event of breakage.

' It will be understoodthat certain variations in structure anddesign may be adopted within into releasable engagement with the teeth of the drive ring, the inner ends of said pawls bearing against said abutment, a cam member disposed over said pawls and having cammed edges adapted to engage the pawls, a manually-operable lever operatively connected to said cam member whereby the latter may be moved in opposite directions to reverse positions or to an intermediate neutral position, said cam member when moved in opposite directions selectively interposing said member between said pawls and the drive ring for one-Way driving engagement of the drive ring with the chaser plate and when in a neutral position permitting the pawls to remain in engagement with said teeth and hold the ring locked to the plate, and a detent member arranged to engage said cam member and releasab-ly maintain the latter in a selected position.

' WILLIAM O. THEWES. 

